Titanium oxide belongs to photosensitive semiconductor materials and has been applied widely in fields of the photocatalytic hydrogen generation, organic matter degradation and solar energy batteries. In recent years, the application potential of titanium oxide in other fields is increasingly discovered, and as a catalyst carrier and a lithium ion battery cathode material, titanium oxide attracts more and more attention in the fields of applications to energy, environment, etc. For example, in the field of catalyst, the preparation of catalytic materials having double functions of being carrier and catalyst can greatly reduces cost, and thus has an attractive prospect of industry. Compared with the conventional catalyst inert carrier, such as γ-Al2O3, titanium oxide has favorable catalytic activity and it is a catalyst carrier material with great potential [1]; in the field of lithium ion batteries, the unique crystal structure of titanium oxide facilitates insertion/extraction of lithium ions, and compared with the conventional carbon material cathode material, titanium oxide as a new generation of cathode material has low cost, safe use, and low possibility of causing explosion [2]. Meanwhile, with the growth of nanotechnology, titanium oxide with nanotopography or pores is increasingly developed, which promotes the application of titanium oxide in these fields.
As a catalyst carrier or a lithium ion battery cathode material higher specific surface area of titanium oxide is required. For instance, nano TiO2 as a catalyst carrier has high catalytic activity, but the excessive small size of granules causes difficult recovery and utilization, the easy agglomeration, and great reduction of the specific surface area after calcination molding result in significant decrease of the catalytic activity. The specific surface area of TiO2 prepared by anatase type TiO2 particle molding or lamellar titanate ion exchange is lower than 30 m2/g, porous titanium oxide with high specific surface area is generally obtained by sol-gel method, but industrial production by sol-gel method is impossibly realized because of complex process, expensive raw material and possible environmental risks.
In light of above problems, the studying team successfully takes potassium titanate as raw material to prepare mesoporous titanium oxide [3] (Zl0316827.5) with high specific surface area through a strengthened solid phase microstructure conversion process. The specific surface area of the prepared mesoporous titanium oxide is higher than 50 m2/g. The mesoporous titanium oxide has highly crystallized mesopores, needs no template agent in synthesis, has simple process and low cost, and thus is suitable for bulk production. On this basis, the pore structure of the mesoporous titanium oxide can be adjusted as required according to the method disclosed in the patent [4] (PCT/CN2007/070428).
However, as a catalyst carrier and a lithium ion battery cathode, mesoporous titanium oxide material has some disadvantages that: (1), as a carrier, titanium oxide easily reacts with metal precursors during preparing catalyst because of strong hydrophilicity, and thus is unfavorable to dispersion of metal active components; and (2), as a lithium ion battery cathode, the larger specific surface area causes side reaction occurring on the contact surface between an electrode and electrolyte.
Currently modification based on titanium oxide is mainly organic matter modification based on titanium oxide nano particles, in which the soluble dispersion capacity of titanium oxide is changed through interface behavior of organic matter [5]. On the one hand, mesoporous titanium oxide, as described above, is superior to nano titanium oxide in application; and on the other hand, inorganic matter modification with direct use of organic matter is not benefit to practical application of industrialization because molecules of organic matter is easily decomposed at high temperature and in acid or alkaline conditions.
The inventor has discovered in research that mesoporous titanium oxide can satisfy the requirements of being a catalyst carrier and a lithium ion battery cathode better if using inorganic matters which are inert to acid and alkali and high temperature, such C, Si, S, P and Se, to improve the property of pores of mesoporous titanium oxide.